Electrical power transmission protectors with component grippers, and related methods

ABSTRACT

A dielectric cover for protecting a component of an electrical power transmission system, the dielectric cover comprising: an enclosing part having enclosing portions that are configured for relative movement to each other to enclose the component; and a gripping part having gripping portions that are configured for relative movement to each other to grip the component, the movement of the gripping portions being independent of the relative movement of the enclosing part.

BACKGROUND

The apparatus and method disclosed here relate to the field ofelectrical power transmission and distribution. There exists a varietyof covers used to insulate components of electrical power systems fromshort circuits caused by contact with animals and birds. Hingedtwo-piece covers and one-piece snap on covers are examples. These coversmay be installed remotely by one or more users. Cutout covers, bushingcovers, and lightning arrestor covers are some examples.

The inventor's own prior patent documents disclose dielectric covers forprotecting components of electrical power transmission systems, seeUnited States patent publication no. 20080123254 and PCT publication no.WO2011094870, as well as methods of making such protectors. Otherprotectors are available. In general, these protectors are hingeddevices or similar configurations.

SUMMARY

A dielectric cover for protecting a component of an electrical powertransmission system, the dielectric cover comprising: an enclosing parthaving enclosing portions that are configured for relative movement toeach other to enclose the component; and a gripping part having grippingportions that are configured for relative movement to each other to gripthe component, the movement of the gripping portions being independentof the relative movement of the enclosing part.

A method is also disclosed for protecting a component of an electricalpower transmission system, the method comprising: securing a grippingpart of a dielectric cover to the component, the gripping part connectedto an enclosing part having enclosing portions; and after securing thegripping part, moving the enclosing portions relative one another toclose the enclosing portions over the component.

A dielectric cover is also disclosed for protecting a component of anelectrical power transmission system, the dielectric cover comprising:opposed portions that are movable in relation to each other from an openposition to a closed position and define a component enclosing space atleast when in the closed position; a component gripper on a firstportion of the opposed portions, the component gripper being configuredto grip the component independently of a second portion of the opposedportions; and a lock for securing the opposed portions together in theclosed position.

A method is disclosed for protecting a component of an electrical powertransmission system, the method comprising: securing a first portion ofthe opposed portions of a dielectric cover to the component, the opposedportions being movable in relation to each other from an open positionto a closed position; after securing the first portion, moving a secondportion of the opposed portions relative to the first portion to closethe opposed portions over the component; and locking the opposedportions together in the closed position.

An apparatus is disclosed for protecting a component of an electricalpower transmission system, the apparatus comprising: a dielectric coverhaving opposed portions that define, at least when in a closed position,a component enclosing space between a hinge and outer cooperatingflanges of the opposed portions, the outer cooperating flanges havingapertures aligned when in the closed position; and a threaded boltpositioned between one or both of the respective apertures of theopposed portions for securing and moving the opposed portions into theclosed position.

In various embodiments, there may be included any one or more of thefollowing features: Each enclosing portion of the enclosing portions hasa respective hot stick connector. The enclosing portions form aclamshell cover. The gripping part comprises one or more spring latchesfor gripping at least part of the component between the one or morespring latches. The gripping part comprises a pair of spring latchesopposed to one another. Each of the one or more spring latches isterraced to provide plural latch stops for fitting components ofdifferent dimensions. Each of the one or more spring latches has a latchrelease handle. The gripping part is C-shaped. The dielectric cover isshaped to fit a fuse cutout component. The gripping part is C-shaped tofit over, and around side edges of, an upper contact plate of the fusecutout component. The gripping part has a flange guard for covering theupper contact plate. The gripper is shaped to fit an insulator bushing.The gripping part further comprises a split ring spring latch at a baseof the dielectric cover. The split ring spring latch is collectivelyformed at least in part by a plurality of tines. The lock is a fastenerpositioned between apertures aligned in outer cooperating flanges of theenclosing portions when in a locked and closed position. The fastenercomprises a threaded bolt. The dielectric cover has an opened anduninstalled position where the threaded bolt is inserted through arespective aperture in the second portion of the enclosing portions. Thethreaded bolt has an eyelet for a hot stick. The threaded bolt has oneor more lateral handles. The method is done remotely using a hot stick.The method is carried out by a user located outside a safe Limit ofApproach. The threaded bolt has an eyelet for a hot stick, and one ormore lateral handles about the eyelet. The gripping part comprises agripper insert removeably mounted in use to a gripper receiver on one ofthe enclosing portions. Each enclosing portion comprises a gripperreceiver for independently receiving the gripper insert. a lock forsecuring the enclosing portions together in a closed position. Theenclosing portions are connected via a hinge. A pull wire is passedthrough apertures aligned in cooperating flanges of the enclosingportions when in the closed position, at least one end of the pull wirehaving a flange stop and at least the other end having a hot stickconnector. The lock comprises a swing arm with a slot shaped to receivecooperating flanges of the opposed portions when in a locked and closedposition, the swing arm having a pivot axis that passes through aninterface plane defined by the cooperating flanges. Locking the opposedportions together in the closed position.

These and other aspects of the device and method are set out in theclaims, which are incorporated here by reference.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments will now be described with reference to the figures, inwhich like reference characters denote like elements, by way of example,and in which:

FIG. 1 is a perspective view of a cutout cover.

FIG. 2 is a side elevation view of the cover of FIG. 1 being remotelypositioned over a cutout switch using a hot stick.

FIG. 3 is a side elevation view of the cover of FIG. 1 with the grippingportion secured to the cutout switch before the enclosing portions ofthe cover are secured together.

FIG. 4 is a perspective view of the cover of FIG. 1 with the freeportion of the enclosing portions of the cover being moved to close thecover with a hot stick.

FIG. 5 is a side elevation view of the cover of FIG. 1 after securingthe enclosing portions of the cover together.

FIG. 6 is a side elevation view of a cutout cover embodiment withterraced latches for plural cutout switch sizes.

FIG. 7 is a perspective view of a bushing cover with a gripping portion,being remotely positioned over a bushing.

FIG. 8 is a perspective of the gripping portion of the cover of FIG. 7secured to a bushing.

FIG. 9 is a perspective view of the enclosing portions of the clamshellbushing cover of FIG. 7 after being locked together.

FIG. 10 is a rear perspective view of the base and sides of the bushingcover of FIG. 7.

FIG. 11 is a front perspective view of another embodiment of a bushingcover in a closed and locked position.

FIG. 12 is a rear perspective view of the bushing cover of FIG. 11.

FIGS. 13-14 are front perspective views of the bushing cover of FIG. 11.

FIGS. 15A-15B are a sequence of perspective views of the bushing coverof FIG. 11 in the open position, illustrating a method of mounting agripping insert to a first portion of the enclosing portions.

FIGS. 16A-16B are a sequence of perspective views of the bushing coverof FIG. 11 in the open position, illustrating a method of mounting agripping insert to a second portion of the enclosing portions.

FIG. 17 is a perspective view of the gripping insert of FIGS. 15A-B and16A-B.

FIG. 18 is a perspective cut away view of a gripper receiver on theinside of one of the enclosing portions of the bushing cover of FIG. 11.

FIG. 19 is a rear perspective view of the bushing cover of FIG. 11 in anopen position.

FIG. 20 is a bottom perspective view of the bushing cover of FIG. 19with the gripping portion mounted.

FIG. 21 is a front perspective view of the bushing cover of FIG. 20.

FIGS. 22-33 are a sequence of perspective views illustrating a method ofinstalling the bushing cover of FIG. 11 with a hot stick. FIGS. 22-23illustrate the hot stick positioning the open bushing cover onto the topflight of a bushing. FIGS. 24-26 illustrate the closing of the coverusing a pull wire in the hinge flanges of the cover. FIG. 27 illustratesthe cover before being completely closed. FIGS. 28, 28A, and 29-33illustrate the operation of the latch mechanism for locking the bushingcover. FIG. 28A is a close up taken along the 28A circle from FIG. 28.

DETAILED DESCRIPTION

Immaterial modifications may be made to the embodiments described herewithout departing from what is covered by the claims.

Long-distance electricity transmission is typically carried with highvoltage conductors. Transmission at higher voltages reduces resistancepower loss, therefore line voltage for long distance lines is stepped upafter generation by passing it through transformer stations prior tofeeding the power to long-distance transmission lines. Transmissionlines traverse large regions and require numerous support towers. Theconductors in high tension powerlines are typically uninsulated becauseof the cost and additional weight of insulated versus uninsulatedconductors. Because clearances between adjacent energized elements, andenergized and grounded elements, are generally large in transmissionsystems, these systems generally are not at risk for animal-causedfaults or outages.

Substations transform power from transmission voltages to distributionvoltages, typically ranging from 2400 volts to 37,500 volts.Distribution voltages allow for reduced system clearances. These reducedclearances between phase to ground and phase to phase, increase systemsusceptibility to bird or animal caused outages. Electric poles, towers,and other electrical equipment including substations may provideattractive roosts for birds, particularly in treeless regions. If thewings of a bird simultaneously contact a conductor and another objectsuch as an adjacent conductor, support tower or tree, the resultingelectrical short-circuit can kill the bird and also damage the powersystem. The electrical short circuit can further cause electrical systemdamage resulting in power outages.

Further, the nesting of birds in open cavities in electrical systemsincreases the risk that predators will be attracted to the nests andcause a power fault or outage. Predators include mammals such asraccoons and cats, birds such as magpies, and snakes. Predators can alsocause electrical short-circuits that can cause electrical faults oroutages, damage power systems, and kill the predator. Faults caused bybirds and other animals often trigger sensitive relay protectionschemes, resulting in substation lockouts, interrupting service tothousands or possibly tens of thousands of customers and at the sametime damaging expensive substation equipment.

Thus, some electrical power systems are being insulated from shortcircuits caused by contact by birds and other animals. The variety andnumber of proposed solutions for repelling birds and other animals fromelectrocution risks highlights the persistence and magnitude of theproblems created by such undesirable intrusion. Many different types ofscarecrows and other moving devices have been developed to repel birds.In addition to moving devices, various physical structures ofteninvolving spikes or other physical barriers, have been developed todiscourage birds from roosting on structures. Other bird repellingconcepts use electricity or magnetic fields to discourage birdintrusion. Equipment shield and cage devices have been specificallydesigned to block birds and other animals from accessing andshort-circuiting electrical leads, such as described in U.S. Pat. Nos.5,153,383 and 5,485,307.

Generally, the process of retrofitting electrical equipment withdielectric protective covers may be costly and may require powering downthe system. Power down interruptions for the purpose of installingprotective covers can keep a system down for a half a day or longer timeperiods, at great cost. Some systems are operated under the direction ofa regulatory and scheduling authority that controls the system'sdowntime scheduling. In locations with minimal spare power transmissioncapacity, it can be a challenge for a system to get the downtime neededto install protective covers. Because electrical systems are usuallyscheduled for maintenance downtime on a fairly short notice (typically aweek for non-emergency situations), and because scheduled downtime maybe cancelled by the Regulatory Authority on an extremely short notice,there is no guarantee that a component protector will be installedduring a system's available downtime period. As a result, a system canexperience significant delays in protecting their equipment. Thus, insome cases it may not be feasible to de-energize electrical equipment inorder to install covers and as a result covers may need to be installedremotely on energized equipment. In addition, remote installation mayalso be required on energized or non-energized equipment, includingequipment that is difficult to access directly.

Referring to FIGS. 1-5, a dielectric cover 10 for protecting a component12 of an electrical power transmission system 14 is illustrated. Cover10 comprises a gripping part 18 and an enclosing part. The enclosingpart has enclosing portions 20, 22, which are movable in relation toeach other from an open position (FIG. 2) to a closed position (FIG. 5)to enclose the component. Enclosing portions 20, 22 may be opposedrelative to one another as shown. Portions 20, 22 thus define acomponent enclosing space 23 at least when in a closed position (FIG.5). Referring to FIG. 2, portions 20, 22 are illustrated as opened.Enclosing portions 20 and 22 may be configured to meet or contact oneanother in the closed positions along respective enclosing edges orflanges 24, 26 (FIG. 5). Dielectric cover 10 may have an open positionin which enclosing edges 24, 26, of the enclosing portions are likeopened jaws and are spaced to allow entry of the component 12 betweenthe enclosing edges 24, 26 into the dielectric cover 16 (FIG. 2). Such acover 10 may be referred to as a clamshell cover.

Gripping part 18 may be positioned on a first portion 20 of theenclosing portions (FIG. 3). The gripping part or component gripper 18has gripping portions, such as spring latches 54, which are configuredfor relative movement to each other to grip the component 12. Themovement of the gripping portions is independent of the relativemovement of the enclosing portions. Thus, gripping portion 18 may beconfigured to grip the component 12 independently of a second portion 22of the enclosing portions. To install cover 10 the first portion 20 issecured to the component 12 (sequence shown in FIGS. 2-3). In theexample shown the second portion 22 is free to move, for example about ahinge 30, relative to first portion 20 once the gripping part 18 hassecured first portion 20 to the component 12 (FIGS. 3 and 4).

The gripping part 18 may further comprise one or more spring latches 54,for example a pair of latches opposed to one another, for gripping atleast part of the component 12 between the one or more spring latches 54and the one of the enclosing portions 20, 22 (FIG. 2). Latches 54 maycollectively function as a clip that slides on and locks to thecomponent. As the first portion 20 is lowered into place along direction56, component 12, for example an upper contact plate 58, contactsrespective sloped guide portions 60 of latches 54 and biases latches 54outward along directions 62. When respective shoulders 64 of latches 54clear side edges 66 of upper contact plate 58, the latches 54 closetowards one another, enclosing the upper contact plate 58 betweenshoulders 64 and a base-facing flange 68 of cover 10 (FIG. 3). In theexample shown, gripper 18 is C-shaped to fit over and around, forexample clip to, edges 66 of the fuse cutout component 12. Flange 68 maycover the upper contact plate 58 and extend like a table over and beyondplate 58 to reduce or prevent contact between plate 58 and wildlife.Each latch 54 may have a latch release handle 70, for example extendedfrom shoulders 64, to permit manual release of latches 54 in the eventthat a user desires to remove cover 10 from component 12. In the exampleshown the handles 70 also define the sloped guide portions 60 that openthe latches 54 when the part of the component 12 is inserted into thegripping part 18.

To permit remote securing of gripper 18 to component 12, cover 10 mayhave one or more hot stick connectors 36 and 38, for example shown asapertures in first portion 20 (FIG. 2). In the sequence of FIGS. 2-3,connector 38 is engaged and remotely positioned with a hot stick 31 tosecure gripper 18 to component 12. A conventional universal grip-all(“shotgun’) dielectric hot stick 31 may be used for remote operations asshown, although other types of hot sticks may be used.

After securing the first portion 20, the second portion 22 of theenclosing portions is moved, for example swung, relative to the firstportion 20 to close the enclosing portions over the component 12(sequence from FIGS. 4-5). Swinging may also be done with a hot stick31. For example, hot stick 31 may connect to a tool or hot stickconnector on the portion 22 such as an eyelet 29 in a threaded boltfastener 28. Because first portion 20 is secured to component 12 bygripper 18, a lateral force from hot stick 31 through fastener 28 willrotate portion 20 into the closed position as shown.

The enclosing portions 20, 22 may then be locked together in the closedposition, for example using a fastener like a threaded bolt 28 (FIG. 5).In the example shown, locking and moving the second portion 22 may occursimultaneously, as a pointed end 42 of bolt 28 engages aperture 44 infirst portion 20 followed by rotation of bolt 28 with hot stick 31 toscrew bolt 28 securely into aperture 44 (FIGS. 4 and 5). Bolt 28 may bemounted for rotation within an aperture 46 of second portion 22 toensure that rotation of bolt 28 draws corresponding flanges or edges 24and 26 together on rotation once bolt 28 is threadably engaged withinaperture 44. A radial flange 48 on bolt 28 and an unthreadedintermediate portion 50 between a threaded portion 49 and radial flange48 permit rotation of bolt 28 within aperture 46 without relative axialmovement between bolt 28 and second portion 22 (FIG. 4).

Bolt 28 may be installed through aperture 46 by threading bolt 28through aperture 46 until intermediate portion 50 bears within aperture46. Threaded bolt 28 may have one or more lateral handles 52 for exampleabout the eyelet 29 to permit direct rotation by a user wearing thickdielectric gloves (FIG. 1). The combination of eyelet 29 and handles 52permits manual installation or remote installation via a hot stick 31,respectively.

Apertures 44 and 46 may align when in the closed position (FIG. 5). Insome cases bolt 28 may be positioned on outer cooperating flanges 51 and53 of the enclosing portions 20, 22, respectively, such that componentenclosing space 23 is between hinge 30 and flanges 51 and 53 when in theclosed position (FIG. 5). Bolt 28 or another type of spreader may beused to give positive control over at least a portion of the range ofswinging motion required to close the cover 10. Positive controlincludes the ability to precisely control the movement and position ofportions of the cover relative to one another and to the surroundingspace throughout a range of movements from open to closed. Such controlmay be advantageous particularly at the end of a swinging sequence whenportions 20, 22 are almost closed and portions 20 and 22 begin to fittogether. At such a stage bolt 28 acts to pull the portions 20 and 22together, overcoming friction cause by imperfect construction oralignment between edges 24 and 26 about the perimeter of cover 10.

Other lock systems than as shown may be used. For example, the lock maycomprise a pin and slot, cam lock, eyelet and lock, latching mechanism,Velcro™ strips or other suitable mechanisms. A lock in a simple form maybe a mechanism that restricts the opening of portions 20 and 22 whenclosed. The lock may be remotely actuated for example as shown using hotstick 31.

The cover 10 is configured to permit relative movement between enclosingportions 20 and 22. Thus, cover 10 may further comprise a hinge 30between the enclosing portions 20, 22 (FIGS. 1 and 4). The hinge 30 maydefine a pivot axis 45 that is spaced outwardly, for example usingflanges 57 and 59, from the component enclosure 23. Spacing the hinge 30outward increases the radius of curvature at the outer most edges 24 and26, thus reducing the angle of attack when swinging the portions 20, 22into the closed position. In other cases portions 20 and 22 may beconnected by one or more intermediate portions (not shown). Hinge 30 maybe comprised of one or more hooks 32 and rods 34 (FIG. 1), a snap hinge(FIG. 9), a piano hinge, a living hinge, or other suitable hingestructures.

Referring to FIG. 6, a variant of the gripping part 18 from the cutoutcover 10 of FIG. 3 is illustrated. Each of the one or more springlatches 54 is terraced to provide plural latch stops 54′ and 54″ forfitting components 12, in this case upper contact plates 58, ofdifferent dimensions. Terracing in the example shown, which includes apair of opposed latches 54, may include progressively smaller separationdistances 72 and 74 with distance from flange guard 68. Thus, arelatively narrower upper contact plate 58 than the one illustrated mayonly need to be positioned past stops or latches 54″. Lateral shoulders55 may grip sides 67 of upper contact plate 58 in order to secure cover10 in place on component 12. Latch release handles 70 may be accentuatedto facilitate remote unlatching, and may include one or more hot stickconnectors (not shown).

Referring to FIGS. 7-10 a cover 10 shaped to fit an insulator bushingcomponent 12 is illustrated. The bushing cover of FIGS. 7-10 has manyparts similar to those found in cutout cover illustrated in FIGS. 1-5.Installation is carried out in a method similar to the cutout cover. Ahot stick 31 remotely positions first portion 20 over bushing 12, whichmay include one or more wires (FIG. 7). Hot stick 31 is able to positionfirst portion 20 through a hot stick connector such as lateral eyelet 76in first portion 20 (FIG. 9).

The gripping part 18 of cover 10 is illustrated in FIG. 7 with a splitring spring latch 54, collectively formed by a plurality of resilienttines 80 tapered downwardly at a base 78 of the dielectric cover 10.Tines 80 are distributed around a split ring flange 82 forming base 78.Split rings include rings that span fewer radians than a full circle butmore than half a ring. Example split rings include ⅔ or ¾ of a ring. Inthe example shown flange 82, which also forms part of gripping part 18,has an inner entry diameter 84 that is narrower than a bushing width 86,so first portion 20 may be laterally slid into position below an upperrow or flight 88 of bushing insulator 12 (FIGS. 7-8). Once in positionflange 82 prevents axial removal of first portion 20 from bushing 12while tines 80 restrict against lateral removal and may providesufficient friction against bushing 12 to allow second portion 22 to beclosed over first portion 20 without first portion 20 rotating aboutbushing 12. In other cases first portion 20 may be axially slid over toprows or row 88. To facilitate the lateral entry used in the example,lateral notches 90 may be etched out from the radially outermost tines80 to facilitate bending of tines 80 on contact with bushing 12 (FIGS. 7and 10). Tines 80 may be used to accommodate various widths of bushinginsulators and insulator shafts. Tines (not shown) may also be providedon base 79 of second portion 22.

Once first portion 20 is secured by tines 80, second portion 22 may beclosed over secured first portion 20 (FIG. 9). A lock 21 may facilitateclosing. As shown, hot stick 31 may be repositioned to grip hot stickconnector, for example eyelet 92, located on lock latch 94 pivotallymounted on second portion 22. Latch 94 serves two purposes. One, eyelet92 can be gripped by hot stick 31 to close portions 20, 22 (FIGS. 8-9).Two, clasp or latch 94 may be rotated into place to permit latch arm 98to snap over lock rod 99 (FIGS. 9 and 10). On closing, one or moresecondary latches such as snap closures 96 as shown may further lockcover 10 (FIG. 9). One or more edges 24 may overlap on closure, forexample with a single overlap as shown or a double overlap as in thecase of a tongue and groove fitting (not shown), to increase creepagedistance and improve sealing from wildlife entry (FIGS. 9 and 10).

Referring to FIGS. 11-33 another embodiment of a bushing cover 10 isillustrated. Referring to FIG. 21, enclosing portions 20, 22 may beconnected via a hinge 30 and define a component enclosing space 23 asshown. Similar to cover 10 shown in FIG. 7, the cover 10 in FIG. 21 hastines 80 at a base 78 of cover 10, except that tines 80 are positionedon both portions 20 and 22. The tines 80 of either portion 20 or 22 arehalf circles and thus do not form a gripping part 18 that is capable ofgripping the bushing 12. Referring to FIG. 13, entry holes 97 with tines95 are spaced around the perimeter of each portion 20, 22 to permitpassage of one or more wires connected to a bushing (not shown) when thecover 10 is in position. Columnar indents 149 on cover 10 addreinforcing strength to cover 10.

Referring to FIGS. 11-33 the further features of cover 10 will bedescribed by reference to the operation of the cover 10. Referring toFIGS. 15A-B and 17, in a first stage the cover 10 is assembled, forexample by connecting portions 20 and 22, opening the cover 10, andmounting a gripping insert 100 to the portion 20. The gripping part 18may thus comprise a gripper insert 100 removeably mounted in use to agripper receiver 102 on one of the enclosing portions, in this caseportion 20. Referring to FIGS. 16A-B, each enclosing portion 20 and 22may comprise a gripper receiver 102 for independently receiving thegripper insert 100. Thus, either portion 20 or 22 may function as thefirst portion 20, giving the cover 10 more flexibility for installationfrom different sides of the bushing 12. Referring to FIG. 17 insert 100may have a pair of spring latches 54. Latches 54 may define a partiallyor fully ring-shaped inner surface 104 for contacting the bushing 12 inuse. Latches 54 may be extended from respective arms 106 from a backing108, which may have a C-shaped inner surface 110. The attachment oflatches 54 on arms 106 and with surface 110 permits greater lateralflexibility of latches 54 relative to one another when under lateralforce, such as when latches 54 are opening to insert and grip a bushing12. Latches 54 may include respective shoulders 64, which haverespective peaks 65 in between the shoulders 64 and outwardly slopedguide surfaces 60. Thus, referring to the sequence in FIGS. 22-23, asguide surfaces 60 contact bushing 12, the surfaces 60 are biasedoutwards and the bushing 12 enters into contact with the ring-shapedinner surface 104.

Referring to FIGS. 15B, 17 and 18, a gripper receiver 102 may beprovided as discussed. The receiver 102 may take a suitable shape, forexample comprising a slot 112 comprised of upper and lower ledges 114,116, respectively, for receiving an elongate backing 108 of insert 100in between ledges 114 and 116. One or more combinations of rails andfollowers may be provided on insert 100 and receiver 102, for examplerails 118 on receiver 102 and follower fingers 120 on insert 100 asshown. Rails 118 permit proper alignment and positioning of the insert100 within receiver 102. One or more handles 122 may be provided oninsert 100 for manual manipulation of insert 100 into and out ofreceiver 102. The provision of a removeable insert 100 as a grippingpart permits use of a variety of sizes of gripping parts or inserts 100to be used on a particular cover size 10. Thus, the cover 10 may betailored to fit different equipment configurations in the field, whichgives greater flexibility for installing the cover 10.

Referring to FIGS. 22 and 23, once assembled a hot stick 31, such as aclamp stick as shown, connects to hot stick connector 36 on portion 20.Hot stick connector 36 may have a series of indents 39 shaped tocooperate with clamp end 124 of hot stick 31 to permit positive controlover cover 10. Thus, when hook 126 of clamp end 124 passes througheyelet 128 of connector 36, and hook 126 is retracted, spacedprotrusions 130 of connector 36 fit within opposed slots 132 on clampend 124 to prevent rotation of cover 10 about an axis (not shown)defined through eyelet 128. Positive control is beneficial because itmeans that cover 10 may be positioned by hot stick 31 withoutundesirable shifting, pivoting, or accidental release.

Referring to FIG. 23, the cover 10 is secured on bushing 12. Securingmay be accomplished by inserting gripper part 18 in the throat 134between the top row 88 and the second to top row 89 of bushing 12. Theinner shape of portion 20 may facilitate alignment of cover 10 on upperrow 88. For example, one or more inward protrusions 136 may define a rowinsertion gap 138 between a base 78 and protrusions 136 sized sufficientto fit a single or desired number of bushing rows 88. Portion 22 mayhave analogous protrusions 136 as shown. In other cases protrusions 136may take other shapes, such as blades. When secured various wires 93 mayextend through entry holes 97 as shown.

Referring to the sequence from FIGS. 24-26 the enclosing portions 20 and22 may now be closed to enclose the component 12. Referring to FIGS.25-26, a pull wire 140 is passed through apertures 142 in cooperatingflanges 144 of the enclosing portions 20, 22. When in the closedposition (FIG. 32), apertures 142 align so that pulling on one end (hotstick connector 146) of wire 140 using a hot stick 31 as shown will drawthe flanges 144 and hence the portions 20, 22 together to enclose thebushing 12. Each hot stick connector 146 also forms a stop to preventthe wire 140 from being axially removed from the apertures 142. Theapertures 142 may be positioned at the end of respective slots 148 froma hinge edge 151 of each respective flange 144, so that wire 140 may beinstalled by sliding through the slots 148 into position withinapertures 142. Instead of a wire 140 an elongate member, leash, or othersuitable member may be provided. In other cases a hot stick 31 maysimply push portion 22 to close over portion 20.

Referring to FIGS. 27-33, the closing and locking stages of theinstallation sequence are illustrated. Referring to FIGS. 27-28, theportions 20 and 22 are fully closed, for example using pull wire 140 orby some other suitable method of manipulating cover 10 via hot stick 31(not shown). Referring to FIGS. 28 and 28A, as portions 20, 22 close alateral latch tab 150 on portion 22 is inserted through a correspondingslot 152 in an outwardly extending flange 154 of portion 20. Tab 150 mayhave a ramp guide surface 156 shaped to wedge tab 150 radially inwardsupon entering slot 152. Referring to FIG. 32, once guide surface 156clears slot 152, a trough 158 (FIG. 29) aligns with slot 152 and rampsurface 156 springs outwards to retain slot edge 152 within trough 158.Thus, a first form of latching is achieved.

Referring to FIGS. 28A, 31, and 32, a second form of latching may beachieved. The lock may comprise a swing arm 160 with a slot 162 definedby opposed and spaced guide members 164 (FIG. 31). Swing arm 160 may beshaped to receive cooperating flanges 24, 26 of the opposed portions 20,22 when in a locked and closed position (FIG. 32). The swing arm 160shown has a pivot 161 with an axis (not shown) that passes through aninterface plane defined by the cooperating flanges 24, 26 (FIG. 32). Ahot stick connector 166 on arm 160 permits remote operation via a hotstick 31 (FIG. 31). A fastener (not shown) may be inserted through swingarm 160 and flange 154. When closed a protrusion 170 on flange 154 mayextend into an aperture 168 on swing arm 160 (FIG. 31). Referring toFIG. 30 the swing arm 160 may have a protrusion 171 mating with anindent 173 in portion 22 to maintain the arm 160 in an open positionuntil a sufficient manual force such as from a hot stick 31 dislodgesthe protrusion and permits the arm 160 to swing downwards.

The covers 10 shown in the Figures may incorporate one or more entryholes 97 surrounded at least in part by tines 95 (FIGS. 1 and 9 forexample). Tines 95 accommodate components with various dimensions. Forexample, in FIG. 1 tines 95 accommodate one or more wires 93 passingthrough cover 10. Slots or holes 97 may be circular (FIG. 9), oblong(FIG. 1), or other shapes, for various purposes such as permitting entryof multiple adjacent wires (FIG. 3, oblong hole 97). In one case asingle entry hole 97 may extend from base 78 to the top of the cover 10,and in some cases even to the hinge of the cover 10. The lock, such asswing arm 160 may be located at or near the base 78 to maximize thelength of a single elongate entry hole 97.

Referring to FIG. 2, one or more steps of the method such as securing,closing, and locking may be carried out while the electrical powertransmission system 14 is energized. Such a method may be advantageous,because it allows cover 10 to be placed and installed with ease by auser 33 outside a safe Limit of Approach, for example Limit of Approach89B. In some embodiments cover 10 may be remotely placed into a positioninside a safe Limit of Approach when the electrical transmission system14 is energized. This may be done by a single user 33, operating hotstick 31, who is in a position outside of a safe limit of approach.Standard Limits of Approach, for example limits of approach 89A-B aregenerally set by the IEEE for live electrical systems. It should beunderstood that the Limits of Approach may vary according to region. Thelimits of approach, referenced here by 89A-B around energized equipmentgenerally widen as the voltage increases. For this purpose, hot stick 31may be provided in a length that is suitable for the various Limits ofApproach standards in all jurisdictions. Other suitable techniques maybe used, for example, anchoring, magnetic attachment, adhesiveattachment, and attachment to a liveline tool, including suspending. Insome embodiments, the component 12 comprises non-energized, for examplegrounded, electrical equipment that is located in close proximity toenergized equipment of system 14 and thus lies within the Limit ofApproach of the adjacent energized equipment. In some embodiments, thecomponent 12 comprises energized or non-energized, for example grounded,electrical equipment that is located within system 14 in a spatialconfiguration that makes direct access difficult to accomplish.

Although most of the dielectric covers 10 illustrated in this documentare shaped to fit bushings (not shown) for pole-mounted transformers orcutout switches, dielectric covers 10 may be made to fit othercomponents of an electrical power transmission system. Other suchcomponents include pole-mounted transformers, dead ends (for examplewire termination, overhead and underground), ampacts, lightningarrestors, and pin type insulators to name a few.

Apertures or holes may be partial apertures, for example slots. Tinesmay be made of material resistant to animal or plant incursion.Cooperating mating combinations, such as protrusions 172 and indent 174(FIG. 31) may be positioned along respective portions 20, 22 tofacilitate alignment and closing. Apertures (not shown) may be providedin the side walls or cooperating flanges of portions 20, 22 forpermitting manipulation via a hot stick 31. Covers 10 disclosed here maybe installed manually by hand or using other tools. A spring biasingmechanism may be used to facilitate closing of the cover 10, for exampleby including a trigger within the component enclosing space 23 that maybe tripped upon entry by the component 12. Cooperating tines fromopposed portions 20, and 22 may lie in a plane or may be angled relativeto one another, for example if tines 80 are extended outward as shown inFIG. 11. The base or other portions of tines 80 may have cutouts,indents, or necking to facilitate pivoting. Suitable hinges includeliving hinges, two part hinges, piano hinges, and other hinges such as ahinge formed by a male portion mated with a female portion. More thanone portion 20, 22 may be present, for example three or more enclosingportions. Closing and locking may occur in a single movement.

In the claims, the word “comprising” is used in its inclusive sense anddoes not exclude other elements being present. The indefinite articles“a” and “an” before a claim feature do not exclude more than one of thefeature being present. Each one of the individual features describedhere may be used in one or more embodiments and is not, by virtue onlyof being described here, to be construed as essential to all embodimentsas defined by the claims.

1. A dielectric cover for protecting a component of an electrical powertransmission system, the dielectric cover comprising: an enclosing parthaving one or more enclosing portions that are configured to define acomponent enclosing space to enclose the component; and a gripping parthaving gripping portions that are configured for relative movement toeach other to grip the component, in which the dielectric cover isshaped to fit a component that forms a fuse cutout, with the grippingpart comprising one or more latches for gripping at least part of thecomponent.
 2. The dielectric cover of claim 1 in which each enclosingportion has a respective hot stick connector.
 3. The dielectric cover ofclaim 1 in which the one or more enclosing portions comprises two ormore enclosing portions that are configured for relative movement toeach other and form a clamshell cover.
 4. The dielectric cover of claim1 in which the one or more latches further comprise one or more springlatches for gripping at least part of the component between the one ormore spring latches.
 5. The dielectric cover of claim 4 in which thegripping part further comprises a pair of spring latches opposed to oneanother.
 6. The dielectric cover of claim 4 in which each of the one ormore spring latches is terraced to provide plural latch stops forfitting components of different dimensions.
 7. The dielectric cover ofclaim 4 in which each of the one or more spring latches has a latchrelease handle.
 8. (canceled)
 9. The dielectric cover of claim 1 inwhich the gripping part is C-shaped to fit over, and around side edgesof, an upper contact plate of the fuse cutout component.
 10. Thedielectric cover of claim 9 in which the gripping part has a flangeguard for covering the upper contact plate.
 11. (canceled)
 12. Thedielectric cover of claim 1 in which the gripping part further comprisesa split ring spring latch at a base of the dielectric cover.
 13. Thedielectric cover of claim 12 in which the split ring spring latch iscollectively formed at least in part by a plurality of tines.
 14. Thedielectric cover of claim 1 in which the gripping part comprises agripper insert removeably mounted in use to a gripper receiver on theenclosing part.
 15. The dielectric cover of claim 3 in which: thegripping part comprises a gripper insert removeably mounted in use to agripper receiver on the enclosing part; and each enclosing portioncomprises a gripper receiver for independently receiving the gripperinsert.
 16. The dielectric cover of claim 1 further comprising a lockfor securing the enclosing part in a closed position.
 17. The dielectriccover of claim 3 in which the two or more enclosing portions areconnected via a hinge.
 18. The dielectric cover of claim 3 furthercomprising a pull wire passed through apertures aligned in cooperatingflanges of the two or more enclosing portions when in the closedposition, at least one end of the pull wire having a flange stop and atleast the other end having a hot stick connector.
 19. A method forprotecting a component of an electrical power transmission system, themethod comprising: securing a gripping part of a dielectric cover to thecomponent, the gripping part connected to an enclosing part having oneor more enclosing portions, in which the dielectric cover is shaped tofit a component that forms a fuse cutout, with the gripping partcomprising one or more latches for gripping at least part of thecomponent; and enclosing the one or more enclosing portions over thefuse cutout.
 20. (canceled)